#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int ax, ay, bx, by, cx, cy;
	scanf("%d%d%d%d%d%d", &ax, &ay, &bx, &by, &cx, &cy);
	double ox, oy;
	ox = (ax + cx) / 2.0;
	oy = (ay + cy) / 2.0;
	double obx = ox - bx;
	double oby = oy - by;
	int acx = cx - ax;
	int acy = cy - ay;
	if (acx*obx + acy*oby == 0 && ((obx>0.00000001 || obx<-0.00000001) || (oby>0.00000001 || oby<-0.00000001)))
	{
		printf("yes\n");
	}
	else
		printf("no\n");
	return 0;
}